Can you think of any three-dimensional shape that comprises of exactly two surfaces?

While sitting in the Car, John suddenly finds that one of the wheels was missing. John noticed that a killer is approaching towards him. John cannot get out of the car.

How will John escape?

Cristina was born in 1888. She just had her 30th birthday today how did that happen?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see?

How many Watermelons are there in the below picture?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?

There is a wide field of corn. A goose finds its way into the field and starts running. Can you find out till which point the goose can run into the field?

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

A couple went on a climbing trip. But only the husband returned from the vacation and said that his wife slipped off while climbing and died. On investigating, the local sheriff arrested him saying, 'Your travel agent called. You murdered your wife.'

The man did not inform anyone about the trip. Then how was the agent so sure that it was a murder?